Search for dissertations about: "stability dc power system"

Showing result 1 - 5 of 27 swedish dissertations containing the words stability dc power system.

2. 1. Coordinated Frequency Control Between Interconnected AC/DC Systems

   Author : Danilo Obradovic; Mehrdad Ghandari; Robert Eriksson; Jonas Persson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System Dynamics; Frequency Stability; Small Signal Stability; HVDC Supplementary Power Control; Electrical Engineering; Elektro- och systemteknik;

   Abstract : With ambitions of reducing the environmental pollution, power systems integrate larger shares of Renewable Energy Sources (RES) to phase out conventional thermal and nuclear generators. Since RES (such as wind and solar power) are connected to the grid through power electronics devices, they do not inherently contribute to system inertia. READ MORE

4. 2. Analysis of dc-network stability of VSC-based HVDC grids

   Author : Gustavo Pinares; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power dependent admittance; resonance; HVDC; passivity; Multi-terminal HVDC system; VSC; dc-network stability;

   Abstract : This thesis presents a modelling approach for the investigation of dc-network stability in HVDC grids. It consists on dividing the system under analysis into subsystems such that their individual impact on the stability of the overall system can be studied. READ MORE

5. 3. On Stability Enhancement in AC/DC Power Systems through Multi-terminal HVDC Controllers

   Author : Omar Kotb; Mehrdad Ghandari; Oriol Gomis Bellmunt; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC DC power system; hybrid MTDC; multi-terminal HVDC; small signal stability; VSC-MTDC; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Due to the increasing share of renewable energy sources in modern power systems and electricity market deregulation, heavy inter-regional and cross-border power flows are becoming a commonplace in system operation. Moreover, large-scale integration of renewable energy sources is expected to pace up, therefore new solutions have to be developed to integrate these intermittent sources, which are also characterized by being distributed over large geographical areas, such as offshore wind farms. READ MORE

6. 4. Dynamic Models of Wind Turbines

   Author : Abram Perdana; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency stability; variable-speed; modeling; power system stability; validation; aggregated model; fixed-speed; voltage stability; wind turbine;

   Abstract : The impact of wind power generation in the power system is no longer negligible. Therefore, there is an urgent need for wind turbine models that are capable of accurately simulating the interaction between wind turbines or wind farms and the power system. READ MORE

7. 5. Nyquist Stability Analysis of a VSC-HVDC System with a Distributed Parameter DC-cable Model

   Author : Yujiao Song; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric power transmission; Nyquist stability analysis; VSC-HVDC system; Distributed parameter cable model; Small gain theorem.; Weak AC-grid;

   Abstract : Voltage source converter based high voltage direct current (VSC-HVDC) transmission systems have now been in operation since 1997 as it is a reliable and flexible method of power transmission. This thesis focuses on small signal dynamics of such systems, emphasizing stability properties. READ MORE